Placer-mining machine



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Sept. 18, 1928.

Sept. 1a, 1928.

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IINVENTOR.

Sept. 18, 1928.

F. H. KRUEGER PLACER MINING MACHINE Filed npril 15, 1923 5 Sheets-Sheet3 INVENTOR.

BY l

ATTORNEYS Sgpt. 1a, 1928. 1,684,869

F. H. KRU EGER PLACER MINING MACHINE Filed April 13, 192:5 5Sheets-Sheet 4 I N VEN TOR.

' MMM Sept. 18,1928. 1,684,869

F. H. KRUEGER PLACER MINING MACHINE Filed April 13, 1923 5 Sheets-Sheet5 INVENTOR.

A TTORNEYS Patented Sept. 18, 1928.

warren STATES rnnnmannn. KRUEGER, OF'MILWAUKEE, WISCONSIN.

PLACER-MINING MACHINE.

Application filed April 13, 1923. Serial No, 631,834.

This invention relates to improvements in placer mining machines. 7

It is well known and an established fact that in the greatest number ofcases the gold, platinum or tin in a placer deposit usually lies on orwithin two or three feet of bed-rock. This is so in every case where thedeposition has taken place in a fast flowing stream. The values whichare found concentrated on the bed-rock usually amount to 90 or 95% ofthe total values found.

It has also been demonstrated in various localities, and especially inarid and semiarid countries that the overburden (ground above thebed-rock) will permit of drifting and tunneling without the use of renforcing timbering of any kind. This is due to the fact that in all suchcases the gravel contains a small proportion of natural ce-- ments whichhold the particles together and keep them from caving in for aconsiderable length of time. Also, in numerous instances there arestrata of gravel intermixed with strata of clay; and in such cases theclay strata keep the gravel strata from caving in. Many hydraulic bankswhich have been undermined for a distance of two or SlX feet have stoodup perpendicularly foryears and have not caved in. In Arizona, shaftswere sunk to bed-rock and then drifts dug radially in all directions forten to twenty feet in length on bed-rock and the overburden stood upwell. I

Also, there are many placer properties in this and other countries whichcarry very good values but do not have the proper physical qualities topermit of hydraulic mining, and cannot be practically dredged for thefollowing reasons:

First. The property may carry good values, but the dredgable area may betoo small to warrant the installation of a dredge and permanent camp andprobably a powerplant (such installations cost from $200,000 upwards).

Second. The property may be so isolated thatthe cost would prohibit thetransportation of a heavy and cumbersome dredger.

' Third. A dredger requires a wide out, usuallyfrom M0 feet upwards andcannot be manipulated insmall andnarrow canyons at all. In many cases,the richest values lie up the source of these canyons and at the presenttime there is-no known mechanical apparatus which can dig its way upthese that the values canyons, extract the values and agaln;

,Fourth. A dredger cannot work very well a surface grade exceeding 1Ofeet in a hundred and this is a serious objection in many localities.

Fifth. Another serious objection to the dredger is that when operationsare commenced at a certain locality and it is found do not come u'p'toexpectations and it is deemed advisable to move the dredger to anotherpart of the property, oftimcs several miles, the only way to, get thedredge there is by digging its way through, or by dismantling,transporting and then lie-erecting. The cost, however, in that in mostcases it proceed back either case is so great is prohibitive.

Sixth. As before stated, a dredger requiresa wide cut (140 feetupwards)in which to operate. l't very oftenhappens that the pay streaks may bevery rich, but are too narrow to warrant the operation of the" dredger.V

It must be further understood that in mining gold, tin, platinum andotherlike minerals by mechanical methods, in all cases, the entireoverburden (ground above bed rock) has heretofore been removed, and inpractically all cases this overburden is handled at a loss unless thebed rock values are great enough to warrant the removal of such ground.r

It is one of the objects of this invention to overcome the before mntioned objectionable features and provide a placer mining machine at anominal. cost that can be operated ona very economical basis; and wherethe values are concentrated on bed-rock, the machine can be operated ata very good profit, where the operation of a dr edge would not pay. i, i

A further object of the invention is to provide a placer mining machinewhich will excavate a narrow trench to the desired depth and at the sametime will excavate lateral trenches on or above the bed rock on oppositesides of the main trenchwithout the necessity of removing the"overburden therefrom. i

A further object of the invention is to provide a placer mining machineadapted ion to excavate a trench of inverted T.-shape in crosssectionand remove the earth from, the vertical and lateral portions of'the time excavate lateral extension trenches of from four to ten feet intransverse length on opposite sides of the vertical trench withoutdisturbing the overburden or earth immediately above said lateralextension trenches.

A further object of the invention is to provide a placer mining machineof the type described in wvhich the excavating members may beeasilyraised or lowered to pass over obstructions.

A further object of the invention is to provide a placer mining machineof the boom type in which the excavating portion of the machine may beeasily raised from or lowered into the ground to permit convenientmoving of the machine from place i to place.

A further object of the invention is to provide a placer mining machinewhich will A excavate a vertical trench or ditch with of the samefigure.

lateral under ground cuts, remove the values from the excavated groundand return the worked ground to the trench in one operation whiletraveling over the ground.

A further object of the invention is to provide a placer mining machinewhich is of simple construction, is strong and durable and is welladapted for the purpose described.

With the above and other objects in view the invention consists of theimproved placer mining machine and itsparts and combinations as setforth in the claims and all equivalents thereof.

In the accompanying drawings in which the same reference charactersindicate the same parts in all of the views:

Fig. 1 is a rear view, partly in section and parts broken away, of theimproved placer mining machine, and a section view of the ground toillustrate operation of machine; V

Fig. 2 is a side view of the machine;

Fig. 3 is a front View of the lower portion of the machine;

s Fig. 4 is a vertical sectional view of the lower portion of themachine;

7 Fig. 5 is a vertical sectional detail view of the lower end portion ofthe machine taken on line 55 of Fig. 4; V

Fig. 6 is a transversesectional detail view of one of the lowerexcavating members taken on line 6-6 of Fig. 3; and

Fig. 7 is a similar view taken on line 7-7 drawing the numeral 10Referring to the indicates a power dred ing machine adapted to travelalong the sur ace of the ground and which is provided with a transverseconveyer 11, a perforatedwashing drum 12,

riflles or saving tables 13, a return trough 1 L for directing thecoarser materials to the excavated trench, a lifting boom extendingrearwardly from the trench excavator and a transversely extending drivenshaft 16.

An elongated trench frame 17 ispivotally mounted at its inner or upperend around the transverse shaft 16 and extends outwardly or downwardlytherefrom. The upper end of the trench frame 17 has journaled.

therein a transversely extending counter shaft 16 and the lower endcarries transverse shafts 18 and19 havin flanged idle Wheels 18 and 19therearounrf for guiding an endless conveyer chain 20 provided withbuckets 21 for carryin the valuable minerals and dirt to the surface.The flanged wheels 19 while extending around the shaft 19 are journaledon projecting bearing portions 17" of the trench frame 17. i

The shaft 16 is driven from the power plant 22 by crank and pitman means23 or in any other manner deslred. The elongated trench frame may alsobe raised and lowered from the same power plant by means of the rackarms 24: which are connected at their lower ends tothe trench frameandare actuated by suitable mechanism 25 driven from the power plant inthe ordinary manner to swing the trench frame upwardly or downwardly. V

The shaft 19 between the bearing portions 17 has a sprocket wheel 26engaged bya sprocket chain 27 which leads upwardly and is driven by asprocket 28 from the power plant 22. Said sprocket wheel. 26 is keyed onthe shaft 19 and rotates the same and the said shaft projects outwardlyon opposite sides of the bearings and has mounted thereon spiraleonveyers. 27' reversely threaded with relation toeach other to work theearth towardsthe endless conveyer which carries to the surface. Theperipheral edgeiportion of the spirals are provided with detachableteeth 28' which dig and cut the earth so it can be moved by theconveyers. The outer ends of the shaft l9 also carry supplementalcutters 29 for cutting or digging the outer ends of the transversetrench 30. To provide for all of the earth loosened in the transversetrench being directed to the endless lift buckets 21, guards 31 ofsemi-circular shape in. across section are positioned to the rear of thespiral conveyer so that they "will hold the material in engagement withthe spirals and the spirals will work the material towards the elevatingbuckets.

In operation the trench frame is gradually lowered asthe spiral membersand the ends less conveyer dig into-the earth and when the desired depthor bed rock is reached, the

machine is gradually moved forward to cut the vertical and transversetrench and to elevate the valuable mineral and earth therefrom. Whilethe machine is adapted to handle boulders within its capacity, it caneasily avoid the larger ones by raising the trench frame so that thespiral members will pass over the larger boulders.

In moving forward, the ore from the transverse trenches will be raisedto the surface and the values separated therefrom and the ore returnedto the excavation as a con tinued operation.

From the foregoing description it will be seen that the placer miningmachine is adapted to mine gold, platinum or tin over a considerablearea of bed rock without the necessity of excavating all of theoverburden or earth thereabove.

lVhat I claim as my invention is: I

1. A placer mining machine, comprising a vehicle, a downwardly extendingtrench frame provided with an endless chain and bucket trench diggerswingingly carried by said vehicle for digging a vertical trench, andreversely threaded spiral excavators and conveyers carried by the lowerend portion of the trench frame for digging laterally ex-' tendingextension trenches on opposite sides of the vertical trench and removingthe mineral bearing earth therefrom to a position to be engaged by thebuckets of the vertical trench digger, the spiral portions of saidexcavators extending entirely around the excavators.

2. A placer mining machine, comprising a vehicle, a downwardly extendingtrench frame provided with an endless chain andbucket trench diggerswingingly carried by said vehicle for digging a vertical trench, spiralexcavators and conveyers carried by the lower end portion of the trenchframe for digging laterally extending extension trenches on oppositesides of. the vertical trench and removing the mineral bearing earththerefrom to a position to be engaged by the buckets of the verticaltrench digger,

and means for independently rotating the spiral excavators andconveyers.

3. A placer mining machine, comprising a vehicle having a boom, adownwardly extending trench frame pivotally connected at its upper endto the vehicle, a connection between the boom and the trench frame forraising and lowering said frame, an endless trench digger carried bysaid trench frame for digging a vertical trench, means for rotat ng saidendless trench digger, transversely extending spiral excavators andconveyers carried by the lower end portion of the trench frame fordigging laterally ex-,

tending extension trenches on opposite sides of the vertical trench, andmeans for independently rotating the spiral excavators and conveyers.

4. A placermining machine,'comprising a vehicle having a'boom,-adownwardly ex tending trench frame pivotally connected at its upper endto the vehicle, a connection between the boom and the trench frame forraising and lowering said frame, an endless chain bucket typetrenchdigger carried by said trench frame for digging a vertical trench,means for rotating said endless trench digger, transversely extendinspiral excavators and conveyers carried by the lower end portion of thetrench frame for digging laterally extending extension trenches onopposite sides of the vertical trench, guards positioned at the rear ofsaid spiral excavators and conveyers, andmeans for independentlyrotating the spiral excavators and conveyers. v

5. A placer mining machine, comprising a vehicle having a boom, adownwardly extending trench frame pivotally connected at its upper endto the vehicle, a connection betweenthe boom and the trench frame forraising and lowering said frame, an endless trench digger carried bysaid trench frame for d'gging a' vertical trench, means for rotatingsaid endless trench digger, transversely extending spiral excavators andconveyers carried by the lower end portion of the trenchframe fordigging laterallyex tending extension trenches on'opposite sides of thevertical trench, said spiral excavators and conveyers having toothedperipheral edge portions, and means for independently rotating thespiral excavators and conveyers.

6. A placer mining machine, comprising a vehicle having a boom, adownwardly extending trenchframepivotally connected at its upper endtothe vehicle, a connection between the boom and the trench frame forraising and lowering said frame, an endless trench digger carried bysaid trench frame for digging a vertical trench, means for rotating saidendless trench digger, transverselyextending spiral excavators andconveyers carried by the lower end portion of the trench frame fordigging laterally extending extension trenches on opposite sides of thevertical trench, said spiral excavators and conveyers having toothedperipheral edge portions, guards positioned at the rear of said spiralexcavators and conveyers, and -means for lndependently rotating thespiral excavators and conveyers.

In testimony whereof I aflix my-signature.

FERDINAND I-I. KRUEGER.

